The objective of this project is to investigate the hormonal mechanisms that are responsible for linear growth. Principal areas of investigation include studying short term growth in normal children. In addition, we are investigating the growth of patients with precocious puberty, and the effects of growth hormone and sex steroid administration on linear growth in patients with Turner's syndrome and delayed puberty. We are also attempting to define the optimal dose of hydrocortisone for growth in patients with adrenal insufficiency. In addition, we are examining the effect of inducing pubertal delay in children with extreme short stature, in order to prolong prepubertal growth prior to the pubertal spurt and possibly enhance ultimate height by delaying epiphyseal fusion. Finally, we are investigating the effects of growth hormone therapy on the adult height of non-growth-hormone deficient children with short stature through a randomized, double blind, placebo-controlled clinical trial.